To successfully complete the NET-PD's current ongoing clinical trial. Summary: The Georgia Health Sciences University (GHSU) Movement Disorders Clinic (MDC) is a uniquely qualified and established clinical center for the proposed continuation of a large Phase III, randomized, double-blinded, placebo-controlled clinical trial, which seeks to evaluate the neuroprotective potential of creatine compared with placebo in over 1700 patients. GHSU is seeking support so as to continue all patient follow-up activities necessary for the successful completion of the creatine trial. Follow-up is expected to be completed in 2015. This project is aimed to evaluate the neuroprotective potential of a pharmacological agent designed to slow the progression of PD; the goal set forth by NINDS upon initiation of the NET-PD program. Long-Term Objectives: 1. To delay the progression of PD through the use of medications while maintaining quality of life. 2. Discover indicators of those susceptible to PD and prevent or delay onset of the disease. 3. Ultimately, find a cure for PD.